Filling (with a color, for example) within a path on a 2-dimensional plane is a common problem in computer graphics, and algorithms for how to do it (i.e., path-fill algorithms) are common and well established.
In modern software applications, such as word processors and page-layout applications, it is possible to create pages with text tightly placed around another object such as an image or graphic. The text may wrap around all sides of the object. In such situations, it is necessary to maintain the integrity of words. Given that many such objects can be on a page, and that their shapes can be arbitrary, algorithms to determine how to lay out the text can be quite complex, and unlike path-fill algorithms, are uncommon and not established. This, in turn, means that the computer code and hardware to implement such an algorithm can be time-consuming and error-prone to write and to maintain.